Resizing Pics

[Scarlett]

I have bought an aerial photograph which is 10MB. Each time I re-download it the size changes and gets a lot smaller. It is also a PNG which doesn't open on Picasa, where I would crop it etc. When I crop it with another program I can only get it to aroun 1MB at the most even though I'm only cropping about a quarter of it. Any idea how I can keep it a large size?

[Buenchico]

Everyone should have Irfanview on their computer. At its most basic it's a great image viewing program, which is vastly better than what comes with Windows. However its got some excellent image-editing tools 'under the bonnet' if you explore a bit:
https://www.irfanview.com/

I'm not too sure about exactly what it is that you're trying to achieve but I'll offer you a couple of starting points for working with Irfanview:

To select and crop part of an image, simply click-&-drag a rectangle around the relevant area and press Ctrl and Y together. (Alternatively go to Edit > Crop Selection)

To open up the resizing options, press Ctrl and R together. (Alternatively go to Image > Resize/Resample). You might need to play around with the options there to find what best meets your needs, although just selecting one of the standard size options offered is usually good enough for my needs. (Note that clicking on 'New Size' gives you a bigger list of standard sizes than the one which you see initially).

[Scarlett]

Thank you! I am downloading it but it's asking me if I want to associate extensions with Irfanview- and there's a long list... and I have to either select images, select all or none.
Things like XPM, TTF, MOV, MP3... not sure what I should tick, if at all?

[fender62]

Scarlett, select them all, and let irfan view be your default photo editor, so every pic you want to look at and edit will open irfan view.

[Scarlett]

It says "You want to change current associations and to associate one to many file types with irfanview. Are you sure?" What does this actually mean? At the moment images are usually opened by awful windows thing, and I try and open with Picasa, but Picasa doesn't open PNGs and also is no longer supported. However, Picasa is really good at sorting and finding all photos on my PC! What will happen if I say yes?

[Buenchico]

Just accept it.

From then on if, say, you double-click on an image file it will open in Irfaview. But you can still open an image in Picasa if you want to by going to File > Open in Picasa. Further, you can change your file associations very easily at any time anyway.